where the intersection of their convergent regions is \(|p^2/m_{_2}^2|\le 1\) .
Two linearly independent Gaussian functions constitute the fundamental
solution system of the GKZ-system of Eq.(REF ) in the region \(|p^2/m_{_2}^2|\le 1\) 
which is consistent with the results in the literature. Choosing \(y_{_i}=0\)  in Eq.(46)
of Ref. [1]}, the fourth type Appell functions of the last two terms
are changed into the two Gauss functions above. In the first equation of Eq.(REF ),
we apply the well-known reduction [2]}
\(&&_{_2}F_{_1}\left(\left.\begin{array}{c}\;a,\;b\;\\b\end{array}\right|\;x\right)=(1-x)^{-a}\;.\) 
